Development and simulation of underwater acoustic modem

• Main Author: Song, Ziming
• Other Authors: Arokiaswami Alphones
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Underwater acoustic communication; Modem; OFDM; Channel estimation
• Online Access: https://hdl.handle.net/10356/179363
• Institution: Nanyang Technological University

Increasing interests have been arising in developing communication network systems which are compatible for underwater scenarios. Among all carriers, acoustic signal is preferred for underwater communications, yet the complexity in Underwater Acoustic (UWA) channel requires carefully modified modems comparing to general communication systems designed for air interface. This thesis proposes a modem design for UWA channel including convolutional channel coding, QPSK modulation, Orthogonal Frequency-Division Multiplexing (OFDM) and I/Q modulation with corresponding demodulation modules, with thorough investigations in UWA channel characteristics. Further channel estimation and compensation methods including Least Square (LS) and Linear Minimum Mean Square Error (LMMSE) are introduced to compensate the channel distortion. The designed modem is validated under various Signal-to-Noise Ratio (SNR) through a simulated UWA channel designed based on Bellhop toolbox. The modem designed is proved to have satisfactory BER performance against UWA channel without consuming excessive computational power.